Preheat oven to 350°. Spray a 13x9-inch baking dish with nonstick cooking spray.
In a large Dutch oven, melt 2 tablespoons butter over medium-high heat. Add mushrooms, 2 tablespoons parsley, thyme, and 1 teaspoon salt. Cook, stirring occasionally, for 25 minutes or until mushrooms are tender and liquid has mostly evaporated.
In a large skillet, melt remaining 5 tablespoons butter over medium heat. Sprinkle flour over butter, and cook, stirring constantly, for 3 minutes. Whisk in milk, and cook, stirring constantly, for 6 minutes or until thickened. Remove from heat.
Stir together cheeses. Reserve 1 cup cheese mixture. Add remaining cheese mixture and ½ teaspoon salt to milk mixture, stirring until smooth.
Spread 1 cup sauce in bottom of prepared dish; top with 3 noodles. Spread 1 cup sauce over noodles; top with ¾ cup mushroom mixture. Repeat layers 3 times. Top with 3 noodles, remaining sauce, and reserved 1 cup cheese mixture. Cover with foil.
Bake for 35 minutes or until noodles are tender and sauce is bubbly. Sprinkle remaining 1 tablespoon parsley over lasagna. Let stand for 10 minutes before serving.
Recipe by Paula Deen Magazine at https://pauladeenmagazine.com/cheesy-mushroom-lasagna-recipe/